feat: prevent unnecessary conversions

If content store provides remote cache, we can use remote cache to avoid unnecessary conversions. The layer converted using cache is the same as the layer converted normally, both containing two annotations: LayerAnnotationUncompressed, LayerAnnotationNydusBlob. Also add two constant LayerAnnotations labels. Signed-off-by: breezeTuT <[email protected]>
containerd · Aug 15, 2023 · a138538 · a138538
1 parent a6f4457
commit a138538
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Showing 2 changed files with 25 additions and 1 deletion.
diff --git a/pkg/converter/constant.go b/pkg/converter/constant.go
@@ -20,6 +20,8 @@ const (
 	LayerAnnotationNydusBootstrap     = "containerd.io/snapshot/nydus-bootstrap"
 	LayerAnnotationNydusSourceChainID = "containerd.io/snapshot/nydus-source-chainid"
 	LayerAnnotationNydusEncryptedBlob = "containerd.io/snapshot/nydus-encrypted-blob"
+	LayerAnnotationNydusSourceDigest  = "containerd.io/snapshot/nydus-source-digest"
+	LayerAnnotationNydusTargetDigest  = "containerd.io/snapshot/nydus-target-digest"
 
 	LayerAnnotationNydusReferenceBlobIDs = "containerd.io/snapshot/nydus-reference-blob-ids"
 

diff --git a/pkg/converter/convert_unix.go b/pkg/converter/convert_unix.go
@@ -771,6 +771,28 @@ func LayerConvertFunc(opt PackOption) converter.ConvertFunc {
 			return nil, nil
 		}
 
+		// Use remote cache to avoid unnecessary conversion
+		info, err := cs.Info(ctx, desc.Digest)
+		if err != nil {
+			return nil, errors.Wrapf(err, "get blob info %s", desc.Digest)
+		}
+		if info.Labels[LayerAnnotationTargetDigest] != "" {
+			targetInfo, err := cs.Info(ctx, digest.Digest(info.Labels[LayerAnnotationTargetDigest]))
+			if err != nil {
+				return nil, errors.Wrapf(err, "get blob info %s", desc.Digest)
+			}
+			targetDesc := ocispec.Descriptor{
+				Digest:    targetInfo.Digest,
+				Size:      targetInfo.Size,
+				MediaType: MediaTypeNydusBlob,
+				Annotations: map[string]string{
+					LayerAnnotationUncompressed: targetInfo.Digest.String(),
+					LayerAnnotationNydusBlob:    "true",
+				},
+			}
+			return &targetDesc, nil
+		}
+
 		ra, err := cs.ReaderAt(ctx, desc)
 		if err != nil {
 			return nil, errors.Wrap(err, "get source blob reader")
@@ -825,7 +847,7 @@ func LayerConvertFunc(opt PackOption) converter.ConvertFunc {
 		}
 
 		blobDigest := digester.Digest()
-		info, err := cs.Info(ctx, blobDigest)
+		info, err = cs.Info(ctx, blobDigest)
 		if err != nil {
 			return nil, errors.Wrapf(err, "get blob info %s", blobDigest)
 		}